The present invention is directed to a positioner for a radial arm saw and, in particular, to a positioner which allows quick and simple positioning of numerous workpieces such that each can be cut to a predetermined length which is infinitely variable.
Radial arm saws have always been quite popular with professional carpenters and woodworkers as well as hobbiests who may use the saws infrequently. The popularity of the radial arm saw may rest in its versatility and ease of use. Virtually anyone who uses a radial arm saw with any frequency has encountered the problem of quickly and easily measuring a number of boards to a common predetermined length and thereafter cutting the boards on the saw. Some users nail a block to the saw table to provide them with a guide to use in sawing the boards.
For those who use radial arm saws to cut boards to a predetermined length on a frequent basis, gauges or guides have been developed to ease this process. Unfortunately, many of the previously devised guides are quite expensive, not infinitely adjustable to various lengths, cannot be easily retrofitted to different saws, are not easily moved out of the way when not in use, and/or are difficult to use.
As an example of prior art, a complex lumber measuring device is shown in the Small U.S. Pat. No. 2,747,625. This device functions well to measure a particular cutoff length, but is expensive and designed more for lumber yards or high volume commercial shops and would not be affordable to a typical owner of a radial arm saw.
A number of prior art devices utilize the concept of a slide which is lockable to a fence of the radial arm saw (that is, the upright along which a board is positioned prior to cutting). Such devices are shown in the Siedel U.S. Pat. No. 4,256,000 and Ziegelmeyer U.S. Pat. No. 4,111,088. While such devices often function adequately, they must be removed from the rail in order to allow the saw to be placed in a mode where boards of varying lengths can be easily cut.
One prior art device has been able to partially overcome the problem of quickly moving the positioner out of the way and is shown in the Bucy U.S. Pat. No. 4,412,468. In Bucy, a fixed slide guide is positioned along the back of the fence with a slide that can be rotated to extend forward of the fence. The fence is channelled to allow the guide to fall into a selected channel. While the slide in the Bucy device can be moved to various locations and can be moved out of the path of boards to be cut when different lengths are desired, the fixed spacings between channels prevent easy positioning of the slide in an infinitely large variety of positions and prevent simple sliding of the slide in a down position to a new location.